Caught on video gunning down an unarmed man in the back, former North Charleston Patrolman Michael Slager pleaded not guilty on Wednesday after a federal grand jury indicted him for civil rights violations and lying to investigators.

Slager is also awaiting a state trial after a South Carolina grand jury indicted him on a murder charge last year. At 9:33 a.m. on April 4, 2015, Slager noticed 50-year-old Walter “Lamar” Scott driving with a broken brake light.

According to his dash cam footage, Slager pulled Scott over and requested his driver’s license.

As Slager returned to his patrol car to run a check on Scott’s license, Scott waited a few moments before suddenly exiting his vehicle and fleeing on foot.

While walking to work, a bystander named Feidin Santana witnessed the incident and recorded a video of the shooting on his cellphone.

In the video, Scott appeared to slap something out of the officer’s hands before turning to flee.

As Scott ran away from the officer, the prongs biting into his clothing began to stretch the wires from Slager’s Taser. Instead of chasing after Scott, Slager drew his gun and fired eight shots at Scott.

Four bullets hit Scott in the back and one struck him in the ear. Two of the shots were fatal. Immediately after gunning down Scott, Slager glanced at Santana before speaking into his radio.

According to the incident report, Slager stated into his radio, “Shots fired and the subject is down. He took my Taser.” After Slager cuffed Scott’s hands behind his back, Officer Clarence Habersham arrived at the scene.

Slager immediately rushed back to the spot where he fired his gun and picked up an object. Slager then returned to Scott’s body and appeared to plant his Taser next to him.

In the video, the officers lifted Scott’s shirt to check on his wounds and feel his pulse, but they did not administer CPR. At the time of his death, Scott was wanted on a family court warrant.

Three days later, Slager was fired from the department and arrested for murder. In June 2015, a South Carolina grand jury indicted Slager for the murder of Scott.

On Wednesday, a federal grand jury decided to charge Slager with deprivation of rights under the color of the law, use of a weapon during the commission of a violent crime, and obstruction of justice.

According to his federal indictment, Slager “used excessive force when he shot and killed Walter Scott without legal justification.” Slager also allegedly made false statements to South Carolina Law Enforcement Division (SLED) investigators with the intent to impede the investigation into the shooting.

Instead of admitting that Scott had been running away when Slager opened fire, the former cop falsely claimed that Scott was coming toward him with a Taser when Slager killed him.

If convicted of the deprivation of rights charge, Slager could face life in prison with a potential $250,000 fine.

The other charges each carry maximum penalties of 10 years in prison and $250,000 fines.

Confined to house arrest since January, Slager also faces between 30 years and life in prison for the pending state charge. His murder trial is scheduled to begin on October 31.